Greg KH, Linux kernel developer delivered a keynote in the Linux plumbing conference about the health of the ecosystem. His message was essentially that distributions that don't contribute to the ecosystem have to rely on the whims of others which is unhealthy for them. Here is an introduction the development model and some interesting statistics about the Linux kernel code. Update by TH: Rebuttals are appearing all over the web, like this one by Canonical's Matt Zimmerman ("He's refuting a claim which has, quite simply, never been made. [...] When this sort of thing happens on mailing lists, it's called trolling."), or this one by another Canonical employee, Dustin Kirkland.

First: I don't think the keynote was held to bash Cannonical. Even if they do only small contributions, every contribution is welcome. I think the keynote targeted Ubuntu fanboys who see Ubuntu and Cannonical as the best things ever happened to open source. Cannonical's main contribution to FOSS is probably marketing. The term "Ubuntu" reaches out to people who have never heard of Free Software before. It's cool to reach the mainstream. However keep in mind that FOSS is nothing without its developers. Just don't forget where the developers come from.

Secondly: Some of the counter arguments are a shot in the own foot. Quote from the first one:

Greg considers the "Linux ecosystem" to be GCC, binutils, the Linux kernel, X.org, and a handful of other projects. He disregards most of the desktop stack (including GNOME and KDE), all desktop and server applications, and most anything else that is recognizable to an end user as "Linux".

Yeah, he shouldn't make that statement. I'm a KDE user and thus my main focus of interest is obviously there and only to a lesser extend GNOME. I don't count patches or anything but I'm closely following blog postings etc. So Cannonical has about 3 employees who work on KDE. That's Harald Sitter aka apachelogger, Jonathan Riddell, and maybe Celeste Paul aka seele. There's a page in Kubuntu's wiki that's not really conclusive: https://wiki.kubuntu.org/Kubuntu/Teams It lists one person, Eugene Tretyak, who's directly involved with KDE.

Compare that to openSUSE/Novell: http://en.opensuse.org/KDE_Team
Not counting the members from the community, Novell employs 18 people who work on KDE. That's more than a tenth of Cannonical's entire work force.

The second reaction compares Cannonical's company size with Ubuntu's success. Again, IMHO that's a shot on the own foot. It clearly states that Cannonical's work force didn't grow enough to keep up with its success. Cannonical does not have a work force of adequate size. One "LTS" release every two years that supports desktop components for three years. By comparison: Every openSUSE release (roughly every 6-8 months) is supported for two years. SUSE Enterprise for seven years. Red Hat's enterprise offerings are in the same league of support length.
I don't know how many people Red Hat employs to work on FOSS, but according to Wikipedia Novell employs over 500 free software developers. Cannonical's overall work force is just 130.
So IMHO when Cannonical want to be respected, their contributions to FOSS should keep up with their success. It's even for their own good. Why should a big company deploy Ubuntu on their workstations when they know that Cannonical can't offer them the support they need? They turn to Red Hat or Novell because they know: They don't need to upgrade their desktop PCs after three years, because they have seven years of support. How is Cannonical expected to be financially successful when the paying customers turn to somebody else?
It's not like Cannonical is a little startup with little money. Yeah, Cannonical is a new company, but founded by a billionaire. Cannonical/Shuttleworth has the financial resources to increase Cannonical's work force. It's time to do so or Cannonical's as well as Ubuntu's reputation will shrink.